My Geography teacher has started an experiment which involves me writing about what I have learnt in my lessons and about any geographical news that interests me. My Geography teacher is also going to write a blog about what she teaches me (and therefore what I should have learnt!) and hopefully the two blogs will match up. The idea is that this will not only help me to consolidate what I learn but that it will also help fellow students do the same and keep up to date with current issues.

Thursday, 4 August 2011

Met Office Work Experience - Day 3 (for Wednesday)

I spent my third day at the Met Office talking to various researchers about the work they are doing, how it relates to my EPQ topic and asking them lots and lots of questions (I did have to apologise to one person as I literally spent an hour quizzing them about the thermohaline circulation!). I am unsure as to how much knowledge some of you will have surrounding ocean circulation so some of this may not make a lot of sense - if you hunt around on the blog though you will find various posts on the basics of ocean circulation.

So, first up I had a very long discussion with someone about the thermohaline circulation. For those of you who don't know much about the thermohaline circulation it is the driving force behind the deep currents of the ocean that are collectively referred to as the Global Conveyor Belt. This deep circulation is caused by density changes in oceanic water resulting from changes in temperature and salinity, hence its name ‘thermohaline circulation’, which are caused by cold winds cooling surface waters, the input of freshwater from either precipitation or melting ice, the cooling and freezing of seawater into sea ice or the evaporation of sea water. The basic thermohaline circulation is initiated when denser water (predominately the cooler, saltier water) sinks below the more buoyant water (warm, with a low salt content). Convection penetrates to a level where the density of the sinking water matches that of the surrounding water. When this maximum penetration level has been reached, it will gradually spread into the rest of the ocean. Once the dense water masses have spread into the full extent of the ocean, they will slowly upwell to supply the slow return flow to the sinking regions and replace the surface waters lost - thus driving and sustaining this circulatory movement. Anyway, the discussion I had was focused on the likelihood of it weakening or shutting down and the resulting impacts such an event would have on us. In terms of the UK, if the MOC (Meridional Overturning Circulation) was to significantly weaken or shutdown then the UK would get a lot colder as a slower circulation means a slower heat transfer from the Equator to the Poles and thus a warmer tropics but colder high latitudes. Changes in wind patterns and precipitation would also occur although, in terms of precipitation, the biggest changes would be experienced by those who currently have monsoon climates as a change in the ocean circulation would impact on the movement of the ITCZ. Due to the colder poles, more sea ice is likely to form and this is something that would impact the path taken by the Gulf Stream. The warm moist air brought to us by the North Atlantic Current ( a branch of the Gulf Stream) is what allows us to have a temperate climate, one far milder than countries of the same latitude. However, if the MOC stopped then the path of the Gulf Stream would be altered and it would split at a much lower latitude in the North Atlantic and so we would not get the warm water and moist air that dictates the climate we currently experience. Therefore this would amplify the effects of an MOC shutdown and further cool our climate. When you then factor in the predicted changes due to global climate change, it becomes slightly more complicated. To some extent it is believed that global climate change could, to a certain extent, offset the effects of an MOC shutdown and so they could act to cancel each other out in most of the world. In the Northern Hemisphere though, due to the reduction in speed of the meridional heat transfer, the UK and areas above it would stay cold or perhaps even get colder! So, what would be needed to cause a shutdown or weakening? Well, something that will upset the delicate density differences and so the most likely thing to do this would be an input of freshwater. They are a few possible sources of freshwater that could do this. First is the collapse of ice sheets/shelves in Greenland due to rising sea and air temperatures as not only would you get the obvious freshwater input from that but after ice shelf collapse glacial flow is also increased. Another possibility is the melt of pack ice in the Arctic and the finally possibility is an increase in precipitation as a result of global warming. It is debatable which poses the greatest threat to the MOC as little is known about the stability of ice sheets and shelves in Greenland etc (lots of research is being done at present) and so many think that the most likely threat could come from an increase in precipitation - something that I realised would have an impact but was surprised to know was believed to have the biggest impact in the near future. A question I was quite interested to know the answer to was how much freshwater would be needed to shutdown the MOC and on what time scale would a shutdown be likely to occur. However, no one really knows and research into this is currently being conducted around the world. One thing that was said for certain was that a shutdown is unlikely in the near future and that one would not occur on the time scale portrayed in The Day After Tomorrow (film review on its way soon!)!!! To try and answer these questions lots of models are being used to try and calculate what state the MOC is currently in.

This graph is rather simple but does help when trying to explain some of the theory behind the response of the MOC to freshwater and how it may recover from an input - another area that really intrigues me. So basically along the x-axis is the volume of freshwater and along the y-axis the strength of the MOC/THC. The idea that many have is that the MOC, despite an input of freshwater, will maintain a constant strength until a certain point is reached. At this point, a rapid decline in its strength will be witnessed and then the MOC will fall off its 'track' (kind of onto the bottom line). Therefore, for it to re-initiate, a decline in freshwater would need to occur, which I suppose is like a reversal of the current pattern, for it to get back on 'track'. The idea of this graph originates from some of the thinking behind how the oceans would respond to an input of freshwater and the contrasting ideas produced by models.

The first comes from more complex models which seem to suggest a more gradually weakening in response to a freshwater input. The simple models, upon which the first graph I showed you is based on, suggest something different.

The rapid decline in strength after a certain point has been reached is something that many believe would have in reality.

The same graph as the first one, but based on the response results produced by the complex models, is slightly different.

This graph suggests that a gradually response would occur to an input and that, therefore, a gradual return to normal would occur as freshwater was removed and the density differences restored. Excatly which model is correct has yet to be decided but validating one of thiese models is crucial if we are to understand how the THC/MOC will respond and how it is likely to be re-started. Understanding this is also likely to help with calculating just how much freshwater the MOC can 'cope' with before weakening/shutting down.

Another area that is being researched is what feedback system the oceans are currently in. All of these ideas tie in together and understanding the mechanisms is vital if we are to gain a better understanding of how the ocean responds to different factors.

The negative feedback loop represented, rather simply, above is the state that the models used suggest that the oceans are in; which is the idea that freshwater goes in to the North Atlantic, sinks, and then salt water emerges in the South. However, scientists actually believe that the oceans are in a state of positive feedback instead......

Work into which one the oceans is in is currently being done as by understanding this, it is hoped that more reliable predictions for the future will be able to be produced. Just as kind of a side note, scientists think that the oceans may be able to switch between the two feedbacks mechanisms with this switch being provoked by changes caused to the basic circulation pattern of the oceans, in repsonse to freshwater input.

I realise that this is a bit all over the place but I hope by now you have got the idea that a freshwater input could cause a shutdown or weakening of the MOC and this would have a large impact on the climate of the UK, amongst other countries. Hopefully you we also be able to understand how the alterations of our climate would effect other factors that affect us and other aspects of our lives like, for example, agriculture and food production. Something else though that needs to be taken into account when talking about a possible shutdown is the location of the freshater input. An exact location which would have the largest impact is yet known, but in general, it is believed that any input into the North Atlantic could have a major impact, especially in comparison to the Pacific or Indian Ocean. Again, understanding some of the things above will help aid the discovery of where is the key point in terms of the MOC and this just demonstrates how interlinked all of these things are. During this discussion we covered loads more, hopefully some of which will appear in my EPQ, but I have probably talked about this all a bit too much already! There is some other really interesting stuff that I might right about in a couple days that we also covered - in reflection I do feel a bit sorry for the woman who kindly gave up a lot of her time to talk to me about all of this stuff as I literally bombared her with hundreds of questions!!!

Once last thing I need to mention, which is related to the above, may be of general interest. I don't know if any of you have ever read anything about the thermohaline circulation or meridional overturning circulation but whilst doing research for my EPQ it has confused me how some people switch frequently between THC and MOC and was excatly the difference is. So, I thought who better to ask then the very intelligent scientists at the Met Office! Well, here is the answer............. the MOC is used as to represent the integral across an ocean basin of the meridional flow (south to north movement hence why it is often used to describe the THC in the Atlantic). Given a flow field, the MOC can be precisely defined as a function of depth, or potential density, and latitude. On the other hand, the THC is a less precise concept and is used to describe the whole Global Conveyor Belt circulation. The THC is generally, broadly, taken to mean the part of the circulation that is directly and solely driven by density differences rather than wind stress. However, it is important to note that there are thereotical difficulties in disentangling which forcings are responsbile for a specific part of the circulation and in many cases the MOC is not purely a result of the THC. In many cases, though, the conceptual difficulties may be less severe when considering the changes to the circulation rather than determining the causes of the circulation. Therefore, the reason for some papers alternating between the two is that whilst there are some differences, in some circumstances, both terms are appropriate for use - I hope that explains the small difference!

Then, to finish off what has been an amazing three days, I had a chat with two scientists who are researching the impact of climate change on the ocean ecosystem. These guys were in the Biogeochemistry working group meeting I talked about earlier in the week and so they do a lot of work into CO2 uptake etc. and the idea that phytoplankton can control temperature. Our discussion included many things such as the way in which they model ocean ecosystems and how the models have developed over the years, some of the basics of the cycles involved in the ocean ecosystems and how excatly climate change is likely to alter the delicate ecosystems. This meant that the discussion moved on to the issue of ocean acidification and how studies are being conducted into the impacts this has on ecosystems, especially fish and corals. This is a rather large topic and so, again, I think I will write a seperate post on this over the next few days. At some point in conversation (can't really remember when!) we moved on to a discussion about Daisyworld and the Gaia hypothesis/books. Daisyworld is one of the ways in which James Lovelock tried to represent the ability of the Earth to self-regulate and for a quick idea of what Daisyworld is all about follow the link - Daisyworld animation - its a bit simple but portrays the general idea. I have read the first one and have nearly finished the second one (thanks Millie for getting me to read them as it enabled be to fully participate in the discussion!) and it was quite interesting to get the view of two scientists on the book which is written for the non-scientists about some of the work they are researching.

Anyway, so thats what I got up to during my 3 days at the Met Office (sorry that the posts have been all over the place and written a bit late). I had an incredible time and met some really lovely and highly intelligent people who were more than willing to answer my questions, talk about the work they are doing and offer lots of general advice. There are so many people I need to thank for helping me get into the Met Office, preparing me for the priviledge, allowing me in in the first place, organising many things for me to participate in, for giving up their time to talk to me, allowing me to bombard them with questions and for just being so welcoming whilst I was their. I learnt so much from the experience and its given me a lot to think about in terms of what I want/need to do in the future - I have a lot of thinking to do! It has also reinforced the fact that I know so little about the world of Geography and so I have a lot of reading to do to try and cover as many of the things I didn't quite understand as possible and just expand me knowledge (I will say sorry in advance as a lot of writing is likely to appear on here over the next few weeks!) - I relish the challenge!!! So, all that is left for me to say, apart from another thanks to everyone who has helped make this possible, is that I can't wait to hopefully go back at the end of August!

Geography Films

My Geography teacher is always reminding my class that watching (geography related) films can contribute to the 3 hours of reading time we are supposed to do each week. On both her blog and the Facebook page there are lists of recommended films and so I thought I would start to watch some of them and write a review on them from a student's perspective. If I would recommeded them to a fellow student then I will add the film to my own list below.......

- THE AGE OF STUPID (great film to watch for the energy module as it talks about climate change, energy consumption and production via some interesting case studies)

- THE COVE (this film is very thought provoking and presented the issues surrounding the dolphin trade - before watching this I didn't know a lot about the issue, especially the scale of it in Japan, and it left me feeling very shocked that something like this still exists today in such a developed country)

-ENCOUNTERS AT THE END OF THE WORLD (a great documentary with some simply stunning footage and interesting interviews that collectively provide an insight into life in Antarctica and the important research that is taking place)

-THE CONSTANT GARDENER (a rather sad story about how a drug company exploit the Kenyan population to allow them to test a new drug, despite the fact they know it has harmful side effects - good film for development and globalisation)

- ERIN BROCKOVICH (a good film that presents the negative impacts of the natural gas industry and the extent to which large companies are prepared to go to, to cover this up)

- SLUMDOG MILLIONAIRE (provides an insight into the life of children living in the Indian slums - good film to watch for development)

- GANDHI (a biopic about the life of Gandhi with particular reference to his prominent role in India's struggle for freedom from colonial rule)

- CRY FREEDOM (set in South Africa and tells the true story of Biko and his friendship with a white liberal newspaper editor - good film to watch for development)

- THE PAINTED VEIL (set in China, in the 1920's, and explores the impact of a cholera outbreak on a village, including references as to how religious beliefs make containing cholera even more challenging)

- BLOOD DIAMOND (set amid the explosive civil war overtaking 1999 Sierra Leone; it explores many issues including those surrounding the diamond trade, supply of arms to rebels and child soldiers - good film to watch for development and globalisation module)- THE DAY AFTER TOMORROW (after the Larsen B ice shelf collapses, the thermohaline circulation shutdowns, provoking glacial inception in the northern hemisphere - a good film to watch and then point out the geographical/scientific mistakes!)

- GOODBYE BAFANA (follows the unlikely friendship that forms between Mandela and his prision officer - good for development and globalisation)

- INVICTUS (after 27 years imprisionment, Mandela becomes South Africa's first elected president and this film follows his bid to unite the country via the rugby world cup - good film for development and globalisation)

- DARFUR (a group of international journalists travel to a village in Darfur in search of evidence to persuade the UN that genocide has occured but are forced to live after the Janjaweed turn up and threaten to kill them.... a film to watch for either development and globalisation or the population module but be warned it is very graphic)

Geography Books

I am a bit of a bookworm and often prefer reading a good book to watching a film and so (like I am doing with the Geography films) I am going to read some of the suggested books and write a review on them so I can comment on whether or not I think they are worth reading........

- AN INCONVENIENT TRUTH, Al Gore ( presents the issue of climate change and discusses how it has been caused and the impacts it is likely to have - well worth reading but if you prefer the film version is equally as a good)

- OUR CHOICE, Al Gore (this books follows on from An Inconvenient Truth by offering the solutions Al Gore thinks are required to solve the issue of Global Climate Change)

- THE BOY WHO HARNESSED THE WIND, William Kamkwamba and Bryan Mealer (tells the extraordinary true story of a Malawian teenager who overcame many obstacles to provide electricity and clean water for his village by capturing the energy in both the wind and the sun)

- BLOOD RIVER, Tim Butcher (tells the story of Tim Butchers quest to retrace the journey taken by H.M.Stanley in the 1870's. From this you get an insight into the history of the Congo and the factors that have effected its development - great book for the development and globalisation module as it provides an insight into the impact colonialism has had on Africa)

- GAIA, James Lovelock (presents the Gaia hypothesis which is the idea that the Earth functions as a living organism and so self-regulates to adapt to changing conditions - puts forward some very interesting ideas and really makes you think - it is worth a read!)

- THE REVENGE OF GAIA, James Lovelock (applies the Gaia hypothesis to global climate change - again an intriguing read which presents some interesting ideas and solutions to problems we are likely to face)

About Me

Whilst studying A-levels in Geography, Chemistry, Biology, Maths and History, I became completely fascinated by the Earth Sciences and found them particularly good for feeding my natural curiosity, providing answers to my never ending list of questions! Despite my relentless enthusiasm and frequent question asking, I was quite a quiet student in comparison to the rest of my class so my teacher asked me to start this blog as part of her experiment to test the benefits of incorporating social media into education. The aim was to find out if social networking can be a valuable educational tool and discover how much I actually learnt in lessons. It proved to be a huge success, for both myself and other students, with all my A-level notes still available for students use. I am currently at University studying BSc (Joint Honours) ‘Physical Geography with Oceanography’ and still asking way too many questions! In an attempt to continue to share my love for anything Earth Science-related, and to see if it can have the same benefits at Higher Education, I am trying to continue the blogging and use of social networking. I hope it proves to be a useful and interesting read!

The what, why and how of this blog.......

Hopefully you will have worked this out by now, but this blog is written from a student's perspective and, when combined with my teachers blog, should provide an insight into what I get taught - therefore what I should have learnt - in my Geography lessons. The idea is that this will make it a useful place to go to consolidate your learning; somewhere to go if you didn't quite understand something or missed a lesson. As well as this, posts will be written on anything of general geographical interest whether that be something currently in the news, anything related that I read or watch, anything I do or a topic that I just fancy finding out more about - all of this is designed to broaden our geographical knowledge. When it comes to revision I will try and write up as many notes as possible but it is unlikely that I will be able to cover everything so just let me know if there is anything you would like me to cover. So, thats what the blog is about (simply sharing, with anyone willing to read it, lots of geographical stuff that interests me!) and I am writing it because I tend to get a little enthusiastic about Geography and ask too many questions and so by channeling my interest in this way it will hopefully help you as much as it helps me!!! Whats the best way to use it? Well for starts reading/following the blogs and other resources is the only way you will benefit from them! Secondly, participate and get involved - comment on things, I am bound to get things wrong so correct me, you won't agree with everything I say so tell me what you think and perhaps even suggest things for me to read, watch or look into as I am always looking for new ways to extend my knowledge outside of the classroom. Geography is a discursive subject and, especially with human Geography, for the most part about forming/expressing opinions, so discuss the topics raised via the blogs etc. - trust me, its an easy way to learn!

I am now at University studying BSc (Joint Honours) Physical Geography with Oceanography - to keep my A-level notes separate I have started a new blog for current news and what I am learning in University - anything relevant I will also post on this blog, but please feel free to ask questions or requests posts! I hope students are still finding this a useful resource!

Disclaimer

'What I learnt in Geography this week.....' was created by, with content written by Vicki The Geography Student as part of an experiment conducted by Millie The Geography Teacher.

All posts published are my personal views, apart from where stated otherwise, and not those of the college I attended, my University or associated partners